Field of the Invention
The invention belongs to the technical field of wireless communication, and relates to an uplink and downlink slot time resource configuration method, in particular to an uplink and downlink slot time resource configuration method based on interference perception in a TDD system.
Description of Related Arts
In order to avoid the interference problem brought by flexible slot time configuration, the traditional LTE TDD (Long Term Evolution Time Division Duplexing) network adopts a method of synchronous slot time configuration for each cell, and on the whole network, the TDD uplink and downlink slot time resource configuration is identical. Along with the development of a wireless communication technology, in the future heterogeneous network, the service asymmetry feature of each cell is increasingly obvious, and the same uplink and downlink slot time resource configuration cannot adapt to the service requirements of the network, which results that the resource use ratio of the system is low.
In a single cell (without same frequency interference) scene, the configuration of uplink and downlink resources can be self-adaptively changed according to the need of transmission business, the use ratio of slot time resources is improved and the interference problem of crossing slot time does no need to be considered.
In the deployment of multiple cell TDD (with same frequency interference) systems, although the self adaptivity of the system for transmission business is improved, extra interference types (base station-to-base station interference and terminal-to-terminal interference) are generated in the meanwhile. As shown in FIG. 1 and FIG. 2, it is necessary to effectively evaluate the crossing slot time interference between the cells. The crossing slot time interference comprises base station-to-base station interference and terminal-to-terminal interference, which may severely influence the performance of the whole network, therefore, for the uplink and downlink slot time flexible configuration of the TDD system, the influence on the system performance caused by the crossing slot time interference needs to be solved.
In a document of “An Effective Dynamic Slot Allocation Strategy Based on Zone Division in WCDMA/TDD Systems”, a solution for matching the transmission asymmetry of cell business by dynamically adjusting the uplink and downlink slot time resources in the WCDMA/TDD system is provided, and in this scheme, the coverage of each cell is divided into two zones (an internal zone and an external zone). Wherein, dynamic slot time allocation is only adaptive to the internal zone because of the smaller interference of the crossing slot time of the internal zone on an adjacent cell; in the external zone, all cells keep the same slot time configuration. However, the resource allocation method in the prior art has defects as follows:
1, the slot time resources can not be fully used because the external zone needs to keep a same slot time configuration, and the effect of flexible configuration of the TDD slot time cannot be fully developed;
2, different zones of the same cell need different slot time configuration, which are not compatible with the current standards;
3, the zone division and resource allocation process needs massive calculation, which increases the system burden;
4, in a heterogeneous network, small cells (such as micro cells and family base stations) are difficultly in being divided into different zones, thus the effective dynamic slot time allocation method based on partition on the WCDMA/TDD system is not adaptive anymore.